DC-DC power converters are utilized in situations where one DC voltage at a higher level must be converted to a lower voltage DC level. In certain situations, the current required by the peripheral unit such a micro-processor, can be very high, whereas the voltage can be very low on the order of less than 3.0 Volts and even as low as 1.7 Volts. If this conversion is facilitated at a power supply and then connected to a remote microprocessor on a printed circuit board, the size of the conductor to handle the current and the associated I2R power loss would be large. Thus, it is more desirable to route a higher DC voltage level around the printed circuit board and then do the conversion at the load itself. These types of DC-DC converters are referred to as “Point of Load” (POL) devices.
When a plurality of these types of POL DC-DC converters are disposed within a system, it is desirable to provide control thereof. This typically is facilitated with some type of communication bus, such as serial communication bus, that interfaces with a master computer with each of the POLs having associated therewith some type of controller with memory for storing configuration information. Thus, commands can be sent down to the various POLs to configure the operation thereof, such as the DC operating voltage, and other parameters thereof. In addition, it is also necessary that the systems be synchronized together. Each of the POLs utilize the DC-DC converter that requires some type of switching operation in association with magnetics. The switching control signals are typically developed by some type of pulse width modulated (PWM) and it is desirable to maintain the switching frequencies in a synchronized state.
An additional problem may arise when the master controlling each of the POL DC to DC converters fails. In this circumstance, it is necessary for some other entity to begin acting as master for the POL devices in such a manner that allows the power converter to continue operating in a near seamless fashion.